Matrixing can be carried out when transmitting a first main signal component (the left hand signal component L of a stereo signal), a second main signal component (the fight hand signal component R) and an auxiliary component (a central signal component C), such that a first signal component L.sub.c is obtained which equals L+a.multidot.C and a second signal R.sub.c is obtained which equals R+a.multidot.C, and where the signals L.sub.c, R.sub.c and C are transmitted. Upon reception by a standard receiver not being provided with a corresponding dematrixing circuit, the signal components L.sub.c and R.sub.c are used for supplying via two stereo loudspeakers to a listener. The listener is thus able to perceive the C component transmitted as well, although he has a standard receiver.
More sophisticated matrixing schemes are discussed in J.A.E.S., Vol. 40, No. 5, May 1992, pp. 376-382, as well as in the publication `Matrixing of bitrate reduced audio signals` by W. R. Th. the Kate et al, in Proc. of the ICASSP, 1992, March 23-26, San Francisco, Vol. 2, pp. II-205 to II-208, documents (1a) and (1b) in the list of references.
Compression means for bit rate reducing a signal has been described in published European patent applications 457,390A1 (PHN 13.328) and 457,391A1 (PHN 13.329), the documents (7a) and (7b) respectively in the list of references. Bit rate reducing the above signals L, R and C by means of the above compression means results in these signals being contaminated with quantization noise. The aim of the above compression means is to keep the quantization noise below the threshold of hearing. After transmission and receiving the quantized signals, the quantized signals are dequantized in the receiver, so as to obtain a replica of the signals L, R and C. The original signal components can be retrieved by dematrixing the dequantized signals L.sub.c, R.sub.c and C. It has appeared that the received stereo signal is sometimes affected by quantization noise which has become audible. The above mentioned ICASSP publication has found a solution to this problem in that a prequantization and a corresponding dequantization is carried out on one one of the signal components. The transmitters described in the said publication however still suffer from a deterioration in the transmission characteristics.